Cylinder filling apparatus



Nov. 1, 1966 J. P. ANTOLAK 3,282,305

CYLINDER FILLING APPARATUS Filed Feb. 20, 1964 Ai'y's United States Patent 3,282,305 CYLINDER FELLING APPARATUS John P. Antolak, Chicago, Ill., assignor to General Dynamics Corporation, New York, N.Y., a corporation of Delaware Filed Feb. 20, 1964, Ser. No. 346,319 4 Claims. (Cl. 141-5) The present invention relates to a cylinder filling system which includes a method and apparatus for charging a refillable portable container with a material which is a gas at normal terrestrial atmospheric pressure and temperature, but which may be converted to liquid form any may be stored in a liquid condition at a normal atmos pheric temperature, provided that it be kept in a sealed container under a pressure higher than the normal ambient atmospheric pressure.

Various features of the system may be usable for the charging or storing of containers with different kinds of materials which are normally in a gaseous form under normal atmospheric temperatures and pressures, for example, CO Freon, ammonia, propane, chlorine, etc. The invention is of particular value in connection with carbon dioxide (CO manufactured for sale and distribution in refillable containers, usually in cylindrical form, adapted to be charged with liquid CO at a central location and then distributed by truck, usually without the benefit of refrigeration, to the point where the CO is to be sold or used. Refillable containers used for this type of service are normally required to safely stand an internal pressure of about 900 lbs. per square inch, which is the pressure of CO at a normal room temperature of 22 C. These cylinders are equipped with a valve arrangement which normally is closed to retain the gas or liquid within the cylinder, except when the CO is to be dispensed or withdrawn from the cylinder for use.

Heretofore, it has been the general practice to provide a central point where large amounts of such gases are manufactured or available in bulk and where the gas is to be stored in a large reservoir or tank, the temperature of which is maintained at a very low point, for example in the case of CO below 20 C., so that the vapor pressure need not exceed 20 atmospheres and a reservoir of relatively large capacity can be safely provided at a reasonable cost. However, in filling the relatively small distribution cylinders or other containers from the large reservoir, it has heretofore been necessary to use a. high pressure design pump for forcing the liquid CO into the containers at a much higher pressure than the pressure in the reservoir.

One object of the present invention is to provide a system (including process and apparatus) which is usable with a low pressure design pump of much less initial cost than that of the pump customarily used.

A further object is to provide a system which may be automatic and is more efficient and less expensive to operate than systems heretofore used.

Other features, objects and advantages will be set forth as the description proceeds.

In the disclosed embodiment, one of the objects of the invention is attained by the use of a relatively small pump, which forces liquid CO into the dispensing cylinder at relatively low pressure, for example, only a few atmospheres, in successive spaced increments, and by venting or purging gas during the interval between said increments of charge, thereby periodically relieving the cylinder pressure. Said venting operation preferably is effected automatically through the use of a valve mechanism controlled by the changes in the gas pressure in the dispensing cylinder during the charging and venting cycle.

The drawing accompanying this description and at- Patented Nov. 1, 1966 tached hereto as a part of the specification, is a diagram or flow sheet of an embodiment of the invention in connection with the charging or distributing cylinders with CO in a liquid condition.

Referring to the drawing or flow diagram, the numeral 10 indicates a typical dispensing cylinder in which the CO is distributed to the point of use or sale. The large tank or reservoir 11 contains liquid CO 12, which is kept at a very low temperature, for example, about 20 C. and at a pressure of about 20 atmospheres, by means of refrigerator coils 13 through which there is circulated a supply of brine or other suitable coolant supplied by the refrigerating apparatus 14, which is usually continuously operated by .an electric motor 15. The tank 11 is kept cool by an insulating jacket 16.

The liquid CO contained in the tank 11 is held at a level below the ceiling of the tank 11, so that a gas space 18 is provided for the refrigerating coils 13.

At the bottom of the tank 11 there is a discharge outlet 19 connected to a relatively small electrically driven pump 20. Said pump 20 is connected to the cylinder 10 through a pipe 21, a valve 22, and a pipe 23. To the pipe 23 there is connected a by-pass line 24 for returning gaseous or liquid CO back to the reservoir 11. This by-pass line 24 is closed by a valve 25 when liquid is being supplied to the cylinder through the pump 20 and is opened when the supply of liquid to the cylinder is suspended by the operation of valve 22. The by-pass valve 25, as in the case of valve 22, is pressure-controlled and automatically-actuated by control mechanism later described. Said two valves 22 and 25 are electrically or mechanically linked together and arranged so that when one of the valves is opened, the other is closed, and vice-versa. This actuation of the valves occurs by reason of the change 'of pressure in the cylinder 10 so that when the cylinder pressure differential rises above a predetermined amount, say a few atmospheres or about to 100 lbs. per square inch, for example, about 75 lbs. above the normal reservoir pressure of about 300 lbs, per square inch, the valve 22 will close and the valve 25 will open.

The valve control mechanism which automatically actuates the valves 22 and 25 is arranged so that when the charging part of the whole cycle has continued for a length of time sufiicient to raise the pressure in the cylinder to about 75 lbs. per square inch higher than the pressure in the main reservoir, the charging valve 22 will clos'e and the venting valve 25 will open so that the pres sure in the cylinder will be relieved.

Evaporation of a portion of the increment of liquid which, during the charging portion of the cycle, has been charged into the bottom of the cylinder 10, will then take place, and as the gas is vented back into the reservoir 11 through the bypass 24, the pressure in the cylinder and the pressure in the reservoir will be approximately equalized. At the same time, during this venting operation, the boiling off of the CO from the liquid in the cylinder 10 will be accompanied by a drop in temperature down to the boiling point, about 20 C., of the CO at that particular pressure, in this case, about 300 lbs. per square inch, which is the normal pressure in the reservoir.

When this occurs, the mechanism controlling the valves 22 and 25 will automatically restore the valves to the position of charge and the charging step of the cycle will be repeated until finally the installments supplied to the cylinder by successive charging steps will have filled the dispensing cylinder 10 with the required amount of CO content, such as will be indicated by the line 26 of liquid CO in the cylinder 10. This total amount of charge can be regulated by hand or preferably the whole charging operation can be automatically terminated when the required amount is in the cylinder.

It will be understood that the described operation is such that it is not necessary to deliver the liquid into the dispensing cylinder at a pressure of more than about 375 lbs. In view of the fact that the pressure in the reservoir is constantly maintained at 300 lbs. per square inch, the pump 20 is not required to create a pressure differential of more than 50 lbs. to 100 lbs., generally about 75 lbs. per square inch, as has been indicated.

Due to the cooling effect of the evaporation of CO from the body of liquid CO which has been changed into the dispensing cylinder, the temperature has thereby been automatically reduced so that the pressure in said cylinder is not raised to more than about 375 lbs. per square inch during the charging cycle. However, when the valve 2'7 of the cylinder ll? is closed, the temperature of the liquid in the cylinder will gradually rise and when the liquid in the cylinder has reached a temperature of 72 F. (22 C.) the pressure within the cylinder will have risen to approximately 900 lbs. per square inch.

The control mechanism Any conventional type of electrical or mecahni-cal pressure-controlled mechanism for automatically operating valves 22 and 25 simultaneously, may be employed. However, for purpose of clarification a mechanical mechanism is shown in the diagram, and the valves are shown as separate structures. In the diagram, the valve 22, as shown, has a rotary body or plug 28 having an arcuate channel 29 which is always in communication with the pipe 23 and which is capable of being rocked on its axis so as to expose or close the opening 30 in the end of the pipe 21. The valve body 28 is rocked by an arm or lever 31 which is normally held in the down position by a fixed permanent magnet 32.

Similarly, valve 25 is provided with a rotary plug or body 36 having an arcuate valve passage 37 which will establish communication between the by-pass line 24 and valvepassage 38 when the lever 39, is swung into the dotted line position 40. Said lever 3-9 is held in the dotted line position 40 by a fixed permanent magnet 41.

It will be understood that the permanent magnets 32 and 41 are used to provide a delayed action at each end of the opening or closing operation as the case may be, so that the charging and venting parts of the cycle will each be long enough to effect a pressure change of about 75 lbs. per square inch in the cylinder pressure. The whole cycle may be about 12 seconds, more or less, depending upon conditions.

Describing the motive power means for actuating said valve mechanism in the manner indicated, there is shown a diagrammatica'l arrangement comprising a stationary cylinder 42, the bottom end of which is connected to the vent pipe 43 so as to apply gas pressure from the dispensintg cylinder to the bottom of the ram or piston 44. The piston 44 is connected by means of a link 45 to the valve rock-lever 39. The lever 31 which actuates valve 22 and the lever 39 which actuates valve 25 are caused to move in unison by means of a moving vertical link 46, the ends of which are pivoted respectively, on said levers 31 and 39. Since the pressure in the cylinder 42 below the piston head 44 is approximately that which is in the vent pipe 24 and the dispensing cylinder ll), such pressure may be as high as 300 lbs. per square inch. Consequently, the movement of the valve mechanism is limited by means of a balancing spring 47 connected between the end 4-8 of an extension of the arm 39, and a stationary book 49 which preferably is adjustable up or down to satisfy the requirements of the system.

The motor for charging pump 20 is connected to the electric power line 35, which also serves the refrigerating apparatus 15. The charging pump can be controlled by suitable pressure actuated control mechanism so that it need not operate during the purging starge. However, because of the shortness of the cycle which may be only a few seconds, it is preferred to have the motor run continuously and relieve the delivery-pressure when the charging valve 22 is closed by the control mechanism. This relief may be effected through a safety by-pass 5t) and a suitable pressure relief valve 51 adjusted to open and close at a pressure differential slightly higher than the charging pressure differential, in the present case about 75 lbs.

If desired, the relief valve may be opened and closed automatically by the control mechanism by means which in tlie diagram are shown in dotted lines as a rock arm 52 connected to link 46.

A patent is solicited for any and all herein disclosed patentable subject matter invented by applicant.

The embodiment disclosed herein may be changed or modified without departing from the scope of the invention.

Various features now believed to be new and patentable are set forth in the appended claims.

What is claimed is:

1. For use in a system for charging a container with a desired charge of liquid which at normal atmospheric temperature rapidly becomes a gas unless stored in a sealed container under a pressure considerably above that of the atmosphere, which liquid charge is obtained from a supply of said liquid kept at a temperature substantially below that of a normal atmosphere and at a pressure above that of the atmosphere and approximating the vapor pressure of the liquid at said storage temperature, the apparatus which comprises, in combination,

(a) a pressure pump having an inlet for connection to said supply and an outlet for connection to said container,

(b) a valve in said pump outlet which is in normally open condition for admitting an installment of said liquid into said container so as to raise the temperature and vapor pressure within said container to above the temperature and vapor pressure in said reservoir,

(c) a bypass connecting said container with the reservoir,

(d) a normally closed valve in said by-pass,

(e) means for opening said by-pass valve and closing said pump outlet valve after an installment of said liquid has been pumped into said container, and thus venting gas from said container and into said reservoir,

(f) the combination including means for restoring said valves to their normal condition when the temperature and pressure within the container have been materially reduced, so that a subsequent installment may be admitted into said container 2. A system for charging a refillable portable shipping container with a material which is a gas at normal terrestrial atmospheric temperatures and pressures but may be stored in a liquid condition at a normal atmospheric temperature if kept in a sealed container at a pressure higher than the normal ambient atmospheric pressure, which system comprises, in combination,

(a) a holding-tank for storing a supply of said liquid under a pressure which is a plurality of times the normal atmospheric pressure at sea level, and provided with an outlet for liquid and an inlet for gas,

(b) means for maintaining the liquid in said tank at a temperature considerably less than room temperature,

(c) a pressure pumping means having its inlet connected to said tank outlet and an outlet adapted to be connected to a container which is to be charged,

((1) a valve in the connection between said pump outlet and said container which valve is normally open to deliver liquid into the container,

(e) a bypass between said tank inlet and said container for venting gas from the container back into the tank,

3,282,305 6 (f) a valve in said by-pass which is normally closed container under a pressure considerably above that of when the container is being charged with liquid, and the atmosphere the process which includes, (g) means which are repeatedly responsive to the pres- (a) transferring installments of the desired quantity of sure in the container for closing said liquid valve and opening said by-pass valve when the container pressure rises above a predetermined amount higher than the normal pressure in the tank, while permitting said valves to resume their normal condition after said pressures have been substantially equalized, wherethe liquid from a refrigerated supply of said liquid under pressure into a sealed container by pumping until there is developed Within the container a predetermined gas pressure significantly higher than the pressure of the supply,

(b) ceasing the transfer of the liquid from the supply to the container,

by separate installments of the full charge of liquid 10 are successively fed into the container until the charging operation is completed.

3. For use in a system for charging a container with a desired quantity of liquid which at normal atmospheric temperature rapidly becomes gas unless stored in a sealed l5 container under a pressure considerably above that of the atmosphere, the process which includes,

(a) a pumping liquid from a refrigerated supply of said liquid under pressure into a sealed container until there is developed within the container 2. predetetermined gas pressure significantly higher than the pressure of the supply,

(b) utilizing the pressure differential between the supply and container to vent the gas from the container to the supply to permit evaporation of a portion of (c) utilizing the pressure differential between the supply and the container to vent the gas from the container to the supply until the container pressure is reduced to a predetermined value, thereby permitting evaporation of a portion of the liquid contained in the container and reducing the temperature and vapor pressure of the liquid in the container substantially below said predetermined pressure,

(d) and continuing to alternately introduce liquid and vent gas until the charging of the container has been completed.

References Cited by the Examiner UNITED STATES PATENTS 1,799,591 4/1931 Kiefer 14145 said liquid contamed in the container and reduce the 2,047,827 7/1936 Lamb 62-480 temperature and vapor pressure of the liquid in the 2 678 8/1942 Benz et a1 62 49 container substantially below said predetermined 2387894 10/1945 Fannin 2 X pressure but not below the pressure of the supply 45118 3/1951 St Clair 62 49 hqmd 2,780,899 2/1957 Benson et al 141-5 X (c) and contlnurng to introduce the liquid and vent the 3 195 589 7/1965 HOvda 141 82 X gas until the charging of the container has been completed.

4. For use in a system for charging a container with a desired quantity of liquid which at normal atmospheric temperature rapidly becomes gas unless stored in a sealed LAVERNE D. GEIG'ER, Primary Examiner.

SAMUEL ROTHBERG, Examiner.

H. BELL, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,282,305 November 1, 1966 John Po Antolak It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 13, for "any" read and column 5, line 18, for "a pumping liquid" read pumping liquid 0 Signed and sealed this 5th day of September 1967,,

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

3. FOR USE IN A SYSTEM FOR CHARGING A CONTAINER WITH A DESIRED QUANTITY OF LIQUID WHICH AT NORMAL ATMOSPHERIC TEMPERATURE RAPIDLY BECOMES GAS UNLESS STORED IN A SEALED CONTAINER UNDER A PRESSURE CONSIDERABLY ABOVE THAT OF THE ATMOSPHERE, THE PROCESS WHICH INCLUDES, (A) A PUMPING LIQUID FROM A REFRIGERATED SUPPLY OF SAID LIQUID UNDER PRESSURE INTO A SEALED CONTAINER UNTIL THERE IS DEVELOPED WITHIN THE CONTAINER A PREDETERMINED GAS PRESSURE SIGNIFICANTLY HIGHER THAN THE PRESSURE OF THE SUPPLY, (B) UTILIZING THE PRESSURE DIFFERENTIAL BETWEEN THE SUPPLY AND CONTAINER TO VENT THE GAS FROM THE CONTAINER TO THE SUPPLY TO PERMIT EVAPORATION OF A PORTION OF SAID LIQUID CONTAINED IN THE CONTAINER AND REDUCE THE TEMPERATURE AND VAPOR PRESSURE OF THE LIQUID IN THE CONTAINER SUBSTANTIALLY BELOW SAID PREDETERMINED PRESSURE BUT NOT BELOW THE PRESSURE OF THE SUPPLY LIQUID, (C) AND CONTINUING TO INTRODUCE THE LIQUID AND VENT THE GAS UNTIL THE CHARGING OF THE CONTAINER HAS BEEN COMPLETED. 